摘要:

We show that at about 340 K a large (&bartil;50%) change in the microwave absorption of a single crystal of La0.7Sr0.3MnO3is caused by the application of a field of just a few tens of mT. This large magneto‐impedance occurs at 10 GHz but is absent at 36 GHz, and we demonstrate that these results follow from the frequency and field dependence of the dynamic permeability of a ferromagnetic conductor. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363275

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The calculation of the carrier escape time is important for quantum well devices. In this article a model for calculating the escape time of both electrons and holes is presented. The escape time is found by solving the Schro¨dinger equation by the method of the logarithmic derivative of the wave function which yields: the continuum density of states within a biased quantum well, the proper group velocity, and the partitioning between the thermionic emission and tunneling currents. Excellent agreement between the theoretical and previously reported experimental results for electron and hole escape times is achieved. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363272

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

We consider theoretically phase locking in a simple two‐dimensional Josephson junction array consisting of two loops coupled via a joint line transverse to the bias current. Ring inductances are supposed to be small, and special emphasis is taken on the influence of external flux. It is shown that in the stable oscillation regime both cells oscillate with a phase shift equal to &pgr; (i.e., antiphase). This result may explain the low radiation output obtained so far in two‐dimensional Josephson junction arrays experimentally. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363234

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The transverse current–voltage characteristics of Copper‐ phthalocyanine (CuPc)/Si, PbTe/Si, and PbTe/CuPc/Si junction have been observed in the dark and under illumination. The PbTe/CuPc/Si junction exhibits a strong photovoltaic response with quantum efficiency of 15.4% and power conversion efficiency of 3.46×10−2. The photocarrier is generated in CuPc layer and the carrier is well separated by the steep incline of the potential near the CuPc/PbTe interface. The CuPc/PbTe multilayers show large photoconduction effect in the in‐plane direction. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363235

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Young’s modulus of amorphous Terfenol‐D films has been determined utilizing the resonances of Terfenol‐D/Si composite cantilevers. Its value, 120 GPa about equals that of magnetically saturated Terfenol‐D but displays no &Dgr;Eeffect. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363269

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The intermittent illumination treatment by white light at elevated temperature is proved to be a convenient and efficient method for the improvement of the stability of hydrogenated amorphous silicon (a‐Si:H) films. The effect of the treatment on electrical properties, light‐induced degradation, and gap states of undopeda‐Si:H films has been investigated in detail. With the increase of cycling number, the dark‐ as well as photo‐conductivities in annealed state and light‐soaked state approach each other, presenting an unique irreversible effect. The stabilization and ordering processes by the present treatment can not be achieved merely by annealing under the same conditions. It is shown that the treatment proposed here results in a shift to higher values of the energy barriers between defects and their precursors, and hence an improved stability ofa‐Si:H films. ©1996 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.363270

出版商:AIP    

年代:1996

数据来源: AIP